RESUMO
We present a wavelength tunable, coupled-cavity laser in a standard indium phosphide multiproject wafer shuttle which did not support distributed feedback gratings. The single-mode operation was enabled by reflections from slots in the laser cavity. The wavelength of the laser emission was tunable over 20 nm near a wavelength of 1560 nm via the currents applied to each section of the laser. A maximum side-mode suppression ratio of 46 dB was observed. The delayed self-heterodyne spectrum of the laser showed a Voigt line shape, corresponding to optical linewidths of 3.7 MHz for the Lorentzian and 88 MHz for the Gaussian contributions.
RESUMO
Earlier it was observed that polarization rotation in an AWG built from birefringent waveguides can result in sidelobes in its response. This effect was measured in a polarization sensitive AWG with an orthogonal layout. Now we investigate through detailed simulation whether this effect also exists in polarization desensitised AWGs. It is shown that a dispersion compensated AWG does not suffer from a polarization sidelobe. Alternatively, the AWG can be designed to minimize polarization rotation to suppress the sidelobe.